The move has been expected for 10 days. That's when news broke of Citadel's plans for a so-called prearranged Chapter 11 filing that would have creditors trading a substantial amount of the debt they're owed for 99.5 percent equity in the reorganized company.

Documents that the Las Vegas-based media company filed in New York listed total assets at Oct. 30 of $1.4 billion and total debt of $2.5 billion.

Citadel, which owns and operates 224 radio stations and produces news and talk radio programming for thousands of others, loaded up on debt to fund its acquisition of Walt Disney Co.-owned ABC Radio stations in 2006.

Citadel sought bankruptcy protection to implement a pre-negotiated plan under which it has the support of 60 percent of its secured lenders, the company said in a statement. The plan will convert a $2.1 billion loan into a new $762.5 million term loan, giving senior lenders a pro rata stake and 90 percent of the shares in the reorganized company.

It's not immediately known what, if any, effect the filing will have on Citadel's Chicago stations. WLS-AM is re-signing its afternoon star, Roe Conn, and is close to teaming him with WIND-AM 560 morning co-host Cisco Cotto, although WIND owner Salem Communications has the right to match WLS' offer.

The business will operate as usual in bankruptcy, funded by $36 million in cash on hand under a deal with secured lenders, Citadel said. An outline of the reorganization's terms and a formal Chapter 11 plan are due by April 19.